1. Field of the Invention
The present invention relates to fire fighting equipment, and in particular to a new and improved adjustable support stand for a positive pressure blower device.
2. Description of the Prior Art
Modern techniques of fighting structural fires often involve the use of a positive pressure blower (fan) in order to remove smoke and provide ventilation inside burning buildings. U.S. Pat. No. 4,906,164 to Jackman, et al discloses such a blower. The importance of using such blowers is the quick evacuation of smoke from the building which decreases the potential for smoke damage, and improves visibility and breathing for fire fighters so that they may more efficiently and safely fight the fire.
Because of the unique circumstances in which positive pressure blowers are used, they require several critical features not found in ordinary house fans. In most cases, the blower operates most efficiently when it is set up several feet in front of an open door or window of a burning building. It is important that the funnel of moving air produced by the blower cover the entire opening so that smoke cannot escape back through that same opening (see FIG. 1A). In order to accomplish this, the blower is usually tilted slightly upward, depending on the size and location of the opening in the building.
A pressure blower must also be extremely easy to put into immediate and reliable operation. Thus, is must have wheels for transport, as well as legs for stability once its location is determined. Then, it must be quickly and easily adjustable so that it may be pointed at the opening of the building at the proper angle.
Finally, the blower must be strong, lightweight, and designed to fit into a certain sized compartment on the fire fighting vehicle. It must therefore be operable using gasoline, batteries, or some other portable power source. However, none of these features (size, motor location, or support frame construction) should detract any more than necessary from the overall function of the blower which is to deliver the maximum volume of air possible.
The blower disclosed in U.S. Pat. No. 4,906,164 suffers from two important drawbacks referred to above. First, the large and bulky motor tends to interrupt the free flow of air affecting overall performance. Secondly, adjustment of the support frame is extremely cumbersome and time consuming since it involves a crank mounted to a screw which is manually turned to adjust inclination. Thus, at a time when seconds may be critical, a fire fighter must bend down, grasp, and turn the crank to adjust the level of the blower. Both of these drawbacks are related to the frame upon which the blower is mounted.
Many different fans and frame stands are disclosed in the prior art, including U.S. Pat. Nos. D181,083, D181,416, D192,622, and D327,947; and U.S. Pat. Nos. 2,954,198, and 4,239,259. Although each of these patents shows a fan and some type of support structure, none of them discloses a stand that is easily but reliably adjustable to tilt the fan upward.